Header dyno #'s?

[Wolf Spyder]

Has anyone got any dyno numbers compairing stock, Pacesetter and sprint headers?

[RallyBob]

Has anyone got any dyno numbers compairing stock, Pacesetter and sprint headers?

None that I know of, especially with a comparable combination. Exhaust diameter, carburetor type, camshaft, early engine?, late engine?...lots of variables. I wouldn't expect much from just a Sprint manifold on a stock engine...remember the 1975 Opels were only rated at 5 hp more than the '74 Opels, and this was with the EFI system and the Sprint manifold installed. Same goes with a Pacesetter on a stock engine...they usually feel lethargic below 4500 rpms in fact, far worse than even the stock exhaust manifold. On a modified engine, the Pacesetter starts to make a difference however.

I am currently working on a 'street' GT tubular header, and hope to dyno a bone-stock late-model (low compression) engine with the standard exhaust manifold and exhaust system, plus a 32/36 DGV Weber on a stock intake.

Then I want to pull the stock manifolds, and bolt on the header with another stock intake.

Then I'd like to bolt on a ported intake.

Then a larger diameter performance exhaust system.

Of course, this will require jetting between each dyno session, but it would be interesting to see how each mod affects power and torque. When the header and exhaust are done, I'll be looking for someone in the New England area willing to have his car tested for posterity (dyno shop is in East Hartford, CT).

Bob

Link to dyno shop map: http://www.mapquest.com/maps/map.adp...maplink2&name=

[baz]

form a que only 1 entry per member

[namba209 (R.I.P.)]

form a que only 1 entry per member

Hope you don't mind Baz, but "que" isn't a common word here in the "Colony".

Form a line, only 1 entry per member, is more appropriate, at least on this side of the pond.

[baz]

dont mind at all just wish i had my cay in NE with a stock motor in it

[Travis]

When the header and exhaust are done, I'll be looking for someone in the New England area willing to have his car tested for posterity

Do you have an estimated date?

-Travis

[RallyBob]

Travis, this will be a small tube header for a stock engine. Probably not the best thing for your engine's state of tune.

[Travis]

Yes, I understand it will be optimised for much lower power motors then mine. However, it would still be interesting to see how it compared to my current sprint manifold.... and a good reason to take a day off from work

-Travis

[Opel1_9]

I'll volunteer my bone stock 72 GT as a candidate. No doubt I'll be one of many volunteers.
Ron

[RallyBob]

Thanks guys. I'll post back here when it's ready for fitment. Maybe we can try both cars.

I expect Travis will lose some power due to the smaller tubes and a full exhaust system with two mufflers, but on the other hand some low-end torque gain is entirely feasible. I want to make it pretty quiet too.

When I build the second design (slightly larger tubes for larger displacement engines and/or built-up 1.9/2.0's), then I think Travis will see more benefit. But I'm strictly speculating. The dyno will tell all...

[Gary]

My stock '72 wagon with Solex is available.

[baz]

quick gary do some editing and you will be the only one

[jeff denton]

Oh, man, how I wish there were a chassis dyno near here! Just to play with fuel octane and ignition timing and valve timing...

[calvin]

when I switched from the standard opel header that is always for sale on ebay to the Rhonet (spelling) system that I got from BOB I think I lost some low end however it goes faster and there is more oomph in the middle and I think it breathes better should I by oversight chance to exceed the speed limit

On the other hand now there are weber 48ies and not 40ies (if you pull the manifold off why not change the carb and headers at the same time? Same amount of bolts and you have them off already) of course the cam is different too.

[opelwasp]

Bob, as you perform each dyno run, could you please documrnt and post the setup for each run? Especially jetting and cam profiles.

[Wolf Spyder]

Hope you don't mind Baz, but "que" isn't a common word here in the "Colony".

Form a line, only 1 entry per member, is more appropriate, at least on this side of the pond.

Tis legal in Scrabble!

[RallyBob]

Bob, as you perform each dyno run, could you please documrnt and post the setup for each run? Especially jetting and cam profiles.

That's the plan. Stock cams only though, that's the whole idea of this test, to see the results on a bone-stock engine. Too many variables will skew the results.

Of course, air temp, humidity, gasoline brand/octane/chemical composition and altitude will mess the jetting up for other parts of the country. You really have to tune for your specific region.

[RallyBob]

My stock '72 wagon with Solex is available.

Sorry, GT's only on this one!

[namba209 (R.I.P.)]

Tis legal in Scrabble!

True, but the key phrase I used was "common word". I too have used "que" playing scrabble.

Now getting back on topic, I would really like to see the numbers that will come from the dyno runs. If nothing more than to see if what I'm doing with Willit? has really been worth all the time and money expended.

[hrcollinsjr]

If nothing more than to see if what I'm doing with Willit? has really been worth all the time and money expended.

To quote a great movie line, "You can't handle the truth". But it has been great reading for the rest of us and a real journey for you. So, yes it's probably been worth it because you would have always wondered, what if?

So Ron, keep up the good work and updates on Willit.

Harold